Power-assisted liposuction instrument with cauterizing cannula assembly

ABSTRACT

A method and apparatus is disclosed for mechanically-assisted liposuction treatment. The apparatus includes a hand-holdable housing, an electro-cauterizing cannula assembly, and a reciprocation mechanism. The hand-holdable housing has a cavity adaptable for receipt of a portion of the electro-cauterizing cannula assembly. The electro-cauterizing cannula assembly includes an inner cannula and an outer cannula, each having a distal end and a proximal end and at least one aspiration aperture about the distal end. The inner cannula is disposed within the outer cannula and the inner and outer aspiration apertures are in at least partial registration to form an effective aspiration aperture. The reciprocation mechanism is disposed within the housing and is operably associated with either the inner or outer cannula so that one of the cannulas can be selectively caused to reciprocate relative to the housing while the other is stationarily disposed relative to the housing. As one of the cannulas is caused to reciprocate relative to the other the effective aspiration aperture formed through the distal end of the cannula assembly, is caused to undergo periodic displacement. During aspiration of tissue, high-voltage RF power signals are supplied to the inner and outer cannulas to effect hemostasis about the reciprocating aspiration aperture. Such hemostasis is achieved by causing protein molecules within aspirated tissue to coagulate in response to the high-voltage RF signals being supplied across the reciprocating cannulas. In the preferred embodiments, the amount and rate of such aspiration aperture displacement is controllably adjustable. The cannula assembly is releasably detachable from the hand-holdable housing to facilitate cleaning and sterilization of the cannula assembly and the housing.

RELATED CASES

[0001] The present Application is a Continuation of copendingapplication Ser. No. 08/976,073, filed Nov. 21, 1997, which is aContinuation-in-Part of copending application Ser. No. 08/882,927 filedJun. 26, 1997, now, U.S. Pat. No. 5,795,323, which is a Continuation ofapplication Ser. No. 08/307,000 filed Sep. 16, 1994, now U.S. Pat. No.5,643,198, which is a Continuation of application Ser. No. 07/627,240filed Dec. 14, 1990, now U.S. Pat. No. 5,348,535. Each said Applicationis incorporated herein by reference as if set forth in its entirety.

FIELD OF INVENTION

[0002] The present invention relates generally to a method and apparatusfor performing liposuction and more particularly to a method andapparatus for performing liposuction in a mechanically assisted mannerusing powered expedients.

BRIEF DESCRIPTION OF THE PRIOR ART

[0003] Suction lipectomy, commonly known as liposuction or lipoxheresis,is a well known surgical procedure used for sculpturing or contouringthe human body to increase the attractiveness of its form. In general,the procedure involves the use of a special type of curet known as acannula, which is operably connected to a vacuum source. The cannula isinserted within a region of fatty tissue where removal thereof isdesired, and the vacuum source suctions the fatty tissue through thesuction aperture in the cannula and carries the aspirated fat away.Removal of fat cells by liposuction creates a desired contour that willretain its form.

[0004] Presently, there are two widely accepted techniques ofliposuction and each may be practiced using a conventional liposuctioncannula. The first and most common method proposed by Yves-Gerard Illouzand described in the paper “Illouz's Technique of Body Contouring byLipolysis” in Vol. “I, No. 3, July 1984 of Clinics in Plastic Surgery,involves making regular tunnels at a depth of at least 1 centimeterunder the skin. According to this method, one or two insertions aremade, with radial excursions of the cannula into the fatty tissue of thepatient. The result is a multitude of concomitant sinuses formed belowthe subcutaneous fatty tissue, leaving intact as far as possible theconnections between the skin and underlying tissue, thereby retainingthe blood vessels, the lymphatics and the nerve endings. The secondmethod is the original liposuction procedure proposed by U.K.Kesselring, described in “Body Contouring with Suction Lipectomy”, inVol. 11, No. 3, July 1984, Clinics in Plastic Surgery. According to thetechnique, an entire layer of regular, deep fat is removed by aspirationthrough the cannula, leaving a smooth, deep surface of the residualpanniculus. The space thus created is then compressed, optimallyfollowed by skin retraction.

[0005] Both of these prior art liposuction techniques require that thesurgeon push and pull the entire cannula back and forth almost twentytimes for each insertion made. Typically, twenty to thirty tunnels aremade. This is necessary to ensure even removal of fat in the targetedregion. During this procedure, the surgeon typically massages the fleshin the area of the aperture in the cannula, while at the same time,thrusting the rod in and out of the tunnel. Due to the trauma involvedduring the procedure, the patients' skin, turns black and blue forseveral weeks. Due to the physically exacting nature of the procedure,the surgeon typically comes out of an operating room extremely tired andsuffers from muscular fatigue which prevents him from performing, forsome time thereafter or the delicate operations involved in ordinaryplastic surgery.

[0006] Recently, the use of a “guided cannula” has been proposed by R.de la Plaza, et al., described in “The Rationalization of LiposuctionToward a Safer and More Accurate Technique,” published in Vol. 13,Aesthetic Plastic Surgery, 1918 9. According to the technique, a cannulais used in conjunction with an outer guide sheath through which thecannula can slidably pass while held in place by the handle portion ofguide sheath. Once the cannula and its sheath have been introduced intothe fatty tissue, the sheath guide remains in the tunnel and guidessuccessive introductions of the cannula, keeping it in the same tunnel.While the use of this liposuction technique offers some advantages overthe conventional unguided liposuction cannulas, the guided cannulanevertheless suffers from several significant shortcomings anddrawbacks. In particular, the guided cannula requires manually thrustingthe cannula through the guide sleeve repeatedly for each tunnel.Although this is a less physically demanding procedure, the surgeon mustthrust the cannula even more times through each tunnel to achieve thedesired effect and hence is still easily fatigued and prevented him fromperforming, for some time thereafter, delicate operations involved inordinary plastic surgery.

[0007] In an attempt to solve the above-described problem, U.S. Pat.Nos. 4,735,605, 4,775,365 and 4,792,327 to Swartz disclose an assistedlipectomy cannula having an aspiration aperture which effectivelytravels along a portion of the length of the cannula, thereby obviatingthe necessity of the surgeon to repeatedly push the cannula in and outof the patients' subcutaneous tissue where fatty tissue is to beremoved. While this assisted lipectomy cannula can operate on either airor electric power, it nevertheless suffers from several significantshortcomings and drawbacks. In particular, the device requires an outertube with an elongated slot and a inner tube having a spiral slot whichmust be rotated inside the outer tube to effectuate a travelingaspiration aperture. In addition to the devices overall constructionposing difficulties in assembly, cleaning and sterilization, use with avariety of cannulas and highly effective fat aspiration does not appearpossible.

[0008] Accordingly, there is a great need in the art for mechanicallyassisted, lipectomy cannula which overcomes the shortcomings anddrawbacks of prior art lipectomy apparatus..

OBJECTS AND SUMMARY OF THE PRESENT INVENTION

[0009] Thus, it is a primary object of the present invention to providean improved method and apparatus for performing liposuction whichassists the surgeon in the removal of fat and other subcutaneous tissue(such as but not restricted to gynecomastia) from surrounding tissue,with increased and without promoting physical fatigue.

[0010] It is another object of the present invention to provide suchapparatus in the form of a hand-holdable liposuction, instrument, havinga cannula assembly, in which the location of the aspiration aperture isperiodically displaced as the inner or outer cannulas undergoes slidingmovement relative to the hand-holdable housing.

[0011] It is a further object to provide such a liposuction instrumentin which the rate of reciprocation and the amount of excursion of theaspiration aperture, are selectively adjustable by the surgeon duringthe course of operation.

[0012] An even further object of the present invention is to providesuch a liposuction instrument which can be driven by air or electricity.

[0013] A further object of the present invention is to provide such aliposuction instrument, in which the cannula assembly can be simplydetached from the hand-holdable housing for ease of replacement and/orsterilization.

[0014] An even further object of the present invention is to provide animproved method of performing liposuction, in which one of the cannulasof the cannula assembly is automatically reciprocated back and forthrelative to the hand-holdable housing, to permit increased control overthe area of subcutaneous tissue where fatty and other soft tissue is tobe aspirated.

[0015] Another object of the present invention is to provide apower-assisted liposuction instrument, wherein means are provided alongthe cannula assembly to effecting hemostasis during liposuctionprocedures and the like.

[0016] Another object of the present invention is to provide apower-assisted liposuction instrument, wherein

[0017] Another object of the present invention is to provide such apower-assisted liposuction instrument, wherein the hemostasis means isrealized using RF-based electro-cauterization.

[0018] Another object of the present invention is to provide such apower-assisted liposuction instrument, wherein RF-basedelectro-cauterization is carried out by providing electro-cauterizingelectrodes along the cannula assembly and supplying to these electrodes,RF signals of sufficient power to achieve electro-coagulation and thushemostasis during liposuction procedures.

[0019] Another object of the present invention is to provide such apower-assisted liposuction instrument, wherein the outer cannula isrealized from a non-conductive material and electro-cauterizingelectrode elements are inserted within the aspiration apertures thereofand electrical wiring embedded along the outer cannula and connected toa contact pad embedded within the base portion thereof and wherein theinner cannula is made from an electrically conductive material whichestablishes electrical contact with contact brushes, mounted within thecentral bore of the base portion of the inner cannula.

[0020] Another object, of the present invention is to provide such apower-assisted liposuction instrument, wherein RF supply and, returnsignals are coupled to the cannula assembly by way of the base portionof the outer cannula.

[0021] Another object of the present invention is to provide apower-assisted liposuction instrument, wherein RF-basedelectro-cauterization is realized using electrically conductive innerand outer cannulas which are electrically isolated by way of thin Tefloncoatings applied to the outer surface of the inner cannula and/or theinterior surface of the outer cannula.

[0022] Another object of the present invention is to provide apower-assisted, liposuction instrument, wherein ultrasonic energy, ofabout 50 KHZ is coupled to the inner cannula in order to effect proteincoagulation about the aspiration apertures and thus achieveelectro-cauterization (is hemostasis) during liposuction procedures.

[0023] Another object of the present invention is to provide such apower-assisted liposuction instrument, wherein such ultrasonic energy isproduced by piezoelectric crystals embedded within the base portion ofthe inner cannula and driven by electrical signals having a frequency ofabout 50 KHZ.

[0024] Another object of the present invention is to provide such aliposuction instrument, wherein the electrical drive signals aresupplied to the piezoelectric transducers by way of a pair ofelectrically conductive rails embedded within the interior surface ofthe cannula cavity of the hand-holdable housing of the liposuctiondevice.

[0025] Another object of the present invention is to provide a way ofcarrying out RF-based cauterization within a cannula assembly, whereinthe operating surgeon is enabled to perform lipolysis by driving thepiezo-electric transducers within the base portion of the inner cannulawith signals in the frequency range of about 20-25 KHZ.

[0026] These and other objects of the present invention will becomeapparent hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] For a. fuller understanding of, the objects of the present,invention, reference is made to the detailed description of theillustrative embodiments which are to be taken in connection with theaccompanying drawings, wherein:

[0028]FIG. 1A is a perspective view of a first embodiment of theliposuction device of the present invention;

[0029]FIG. 1B is a cross-sectional view of the liposuction device of thepresent invention taken along line 1B-1B of FIG. 1A;

[0030]FIG. 1C is an elevated end view of the liposuction device of thepresent invention illustrated in FIG. 1A, showing theelectro-cauterizing cannula assembly thereof retained within the cannulacavity of its hand-holdable housing, and alternatively with the hingedlyconnected housing cover panel disposed in an open position for removalof the cannula assembly therefrom;

[0031]FIG. 2A is a perspective, partially broken away view of theelectro-cauterizing, cannula assembly of, the present inventioninstalled in the liposuction instrument of FIGS. 1A through 8C, in whichthe electrically-conductive inner cannula is adapted to freely undergosliding movement within the stationary electrically non-conductive outercannula while electro-cauterization is performed about the aspirationapertures thereof under the control of the surgeon;

[0032]FIG. 2B is a perspective view of the distal end of the innercannula shown in FIGS. 1A, 1B and 2A;

[0033]FIG. 2C is a cross-sectional view of the electrically-conductiveinner cannula taken along line 2C-2C of FIG. 2B;

[0034]FIG. 2D is a perspective, partially broken away view of theelectrically non-conductive outer cannula shown in FIGS. 1A, LB and 2A;

[0035]FIG. 2E is a cross-sectional, view of the electro-cauterizingassembly, taken along line 2E-2E of FIG. 2A;

[0036]FIG. 3A is a plan view of a cauterizing electrode of the presentinvention adapted for insertion within the elongated aperture of theelectrically non-conducting outer cannula;

[0037]FIG. 3A1 is an elevated side view of the cauterizing electrode ofthe present invention taken along line 3A1-3A1 of FIG. 3A;

[0038]FIG. 3A2 is an elevated side view of the cauterizing electrode ofthe present invention taken along line 3A2-3A2 of FIG. 3A.1;

[0039]FIG. 3B is a perspective view of the electricallyconductive collarand brush device of the present invention which inserts with the centralbore formed in the base portion of the electrically non-conductive outercannula of the present invention shown in FIG. 2D;

[0040]FIG. 3B1 is a cross-sectional, view of the electricallyconductivecollar and brush device of the present invention taken along line3B1-3B1 of FIG. 3B;

[0041]FIG. 4A is a cross-sectional view of a portion of a secondembodiment of the liposuction device of the present invention,illustrating an alternative outer cannula retention means;

[0042]FIG. 4B is a cross-sectional view of a portion of a secondembodiment of the liposuction device of the present invention,illustrating an alternative inner cannula retention means;

[0043]FIG. 5 is a cross-sectional view of third embodiment of theliposuction device of the present invention, illustrating a means forcontrolling the mount of excursion of the aspiration aperture along thecannula assembly;

[0044]FIG. 6A is a cross-sectional view of a sixth embodiment of theliposuction device of the present invention, illustrating the use of apair of gas driven piston-type motors and a mechanically-operated gasflow control device disposed in its first state of operation;

[0045]FIG. 6B is a cross-sectional view of the liposuction device of thepresent invention taken along line 6B-6B of FIG. 6A;

[0046]FIG. 6C is a perspective view of the preferred embodiment of themechanically-operated gas flow control device illustrated in FIG. 6A;

[0047]FIG. 6D is a cross-sectional view of the gas flow control deviceof the present invention taken along line 6D-6D of FIG. 6C.

[0048]FIG. 7A is a perspective, partially broken away view of a secondsnap-fit type inner cannula intended for use with the second embodimentof the liposuction device of the present invention;

[0049]FIG. 7B is a cross-sectional view of the outer cannula of thepresent invention taken along lines 7B-7B of FIG. 7A;

[0050]FIG. 8 is a perspective, partially broken away view of a snap-fittype outer cannula intended for use in connection with the secondembodiment of the liposuction device of the present invention;

[0051]FIG. 9A is a plan cross-sectional view of a seventh embodiment ofthe liposuction device of the present invention, having a hand-holdablehousing realized in the form of a pistol-shaped structure havingdetachable barrel and handle portions;

[0052]FIG. 9B is a cross-sectional, partially broken away view of theliposuction device of the present invention taken along line 9A-9B ofFIG. 9A, showing the cam mechanism of the present invention;

[0053]FIG. 9C is an elevated cross-sectional view of the liposuctiondevice of the present invention, taken along line 9C-9C of FIG. 9A,showing the inner cannula disposed at a first position within thecannula cavity of the hand-holdable housing, and the rotary motor andspeed control unit in the handle portion thereof;

[0054]FIG. 9D is a cross-sectional view of a portion of the innercannula excursion control means shown in FIGS. 9B and 9C;

[0055]FIG. 9E is a cross-sectional view of the liposuction device of thepresent invention taken along line 9E-9E of FIG. 9A, showing the rotarydrive wheel of the cam mechanism in operable association with theactuation element which projects through the cannula cavity and isengaged in the slotted base portion of the inner cannula, and alsoshowing in phantom lines the cover panel of the barrel portion disposedin an open configuration permitted insertion or removal of the inner andouter cannulas of the present invention;

[0056]FIG. 9F is an elevated partially broken away rear view of thebarrel portion of the liposuction device taken along line 9F-9F of FIG.9A;

[0057]FIG. 10 is a cross-sectional view of an other illustrativeembodiment of the liposuction device of the present invention, wherein aliposuction device of the present invention is provided, having adouble-acting air-powered cylinder with a magnetically-coupled actuatorand the electro-cauterizing cannula assembly of the present invention isinstalled;

[0058]FIG. 10A is a cross-sectional schematic diagram of the air flowcontrol device employed in the liposuction device shown in FIG. 10, inwhich the control valve thereof is mechanically-linked to thereciprocating piston contained within the cylinder-style reciprocatorwithin the housing of the liposuction device;

[0059]FIG. 11A is a perspective, partially broken away view of a theelectro-cauterizing cannula assembly of the present invention in theliposuction instrument of FIG. 10 in which the electrically-conductiveinner cannula is adapted to freely undergo sliding movement within thestationary electrically non-conductive outer cannula whileelectro-cauterization is performed about the aspiration aperturesthereof under the control of the surgeon;

[0060]FIG. 11B is a perspective view of the distal end of the innercannula shown in FIG. 11A;

[0061]FIG. 11C is a cross-sectional view of the electrically-conductiveinner cannula taken along line 11C-11C of FIG. 11B;

[0062]FIG. 11D is a perspective, partially broken away view of theelectrically non-conductive outer cannula shown in FIG. 11A;

[0063]FIG. 11E is a cross-sectional view of the electro-cauterizingcannula assembly taken along line 11E-11E of FIG. 11A;

[0064]FIG. 11F is a perspective view of the base portion of theelectrically-conductive inner cannula shown in FIG. 11 showing anelectrical contact pad embedded in the outer surface thereof forconducting the conductive rail embedded in the wall surface of thecannula cavity;

[0065]FIG. 11G is a cross-sectional view of the liposuction instrumenttaken along line 11G-11G of FIG. 10;

[0066]FIG. 12A is a plan view of a cauterizing electrode of the presentinvention adapted for insertion within the elongated aperture of theelectrically non-conducting outer cannula shown in FIG. 11;

[0067]FIG. 12A1 is an elevated side view of the cauterizing electrode ofthe present invention taken long line 12A1-12A1 of FIG. 12A;

[0068]FIG. 12A2 is an elevated side view of the cauterizing electrode ofthe present invention taken along line 12A2-12A2 of FIG. 12A1;

[0069]FIG. 13A is a prospective, harshly broken away view of theelectrically-conductive outer cannula employed in an alternativeembodiment of the electro-cauterizing cannula assembly utilizable in theliposuction device of the present invention with suitable modifications;

[0070]FIG. 13B is a prospective view of a distal end of the innercannula shown in FIG. 13A;

[0071]FIG. 13C is a cross-sectional view of the electrically conductiveinner cannula taken along line 13C-13C of FIG. 13B;

[0072]FIG. 13D is a prospective harshly broken away view of theelectrically conductive outer cannula shown in FIG. 13A, over which anelectrically insulating coating such as teflon is applied to theexterior surface thereof;

[0073]FIG. 14 is a cross-sectional schematic diagram of an alternativeembodiment of the electro-cauterizing liposuction instrument of thepresent invention, wherein the reciprocation means is realized using acylinder-style actuator powered by a supply of pressurized air;

[0074]FIG. 14A is a schematic cross-sectional view of the airflowcontrol device employed within the liposuction instrument of FIG. 14;

[0075]FIG. 14B is a prospective, harshly broken away view of theelectrically-nonconductive outer cannula employed in alternativeembodiment of the elector-cauterizing cannula assembly utilized in theliposuction instrument of FIG. 14;

[0076]FIG. 14C is a prospective view of a distal end of the innercannula shown in FIG. 14B;

[0077]FIG. 14D is a prospective harshly broken away view of theelectrically nonconductive outer cannula shown in FIG. 14B, over whichan electrically insulating coating such as teflon is applied to theexterior surface thereof;

[0078]FIG. 14E is a prospective view of the base portion of the innercannula used in the cannula assembly of FIG. 14B, wherein an electricalcontact pad is embedded in the side wall surface thereof of the baseportion for engagement with an electrically conductive rail embeddedwithin the

[0079]FIG. 14F is a cross sectional view of the base portion of theinner cannula taken along ling 14F-14F in FIG. 14E, showing a pluralityof piezo-electrical transducers arranged about the lumen of the innercannula for producing and conducting ultrasonic energy signals forpropagation along the length of the inner cannula; and

[0080]FIG. 14G is a cross sectional view of the liposuction instrumentof FIG. 14 taken along line 14G-14G of FIG. 14, showing a pair ofdiametrically opposed 14G-14G of FIG. 14, showing a pair ofdiametrically opposed electrically conductive rails embedded within theinterior wall surfaces of the cannula cavity of the liposuctioninstrument, which establish electrical contact with a pair of electricalcontact pads embedded within the base portion of the base portion of theinner cannula and are connected to the array of piezo-electrictransducers mounted about the outer lumen of the inner cannula.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0081] With reference to FIGS. 1A through 3D, the first embodiment ofthe liposuction device of the present invention will be described. Ingeneral, liposuction device 1A comprises a hand-holdable housing 2, adetachable electro-cauterizing cannula assembly 4 having inner and outercannulas 4 and 5, and a reciprocation means 6 for causing inner cannula4 to reciprocate means 6 for causing inner cannula 4 to reciprocaterelative to outer cannula 5, which is stationarily disposed with respectto housing 2, This arrangement effectuates periodic displacement of thegeneral location of aspiration along the cannula assembly through thereciprocating movement of inner cannula 4 while permittingelectro-cauterization of aspirated tissue during operation of theliposuction device.

[0082] As illustrated in greater detail in FIGS. 1B, and 2A through 2E,the electro-cauterizing cannula assembly 3 of the present inventioncomprises an electrically-conductive inner cannula 4 and anon-conductive outer cannula 5, each comprising hollow inner and outertubes with distal and proximal ends 4A, 4B and 5A, 5B, respectively.

[0083] As shown in FIGS. 2B and 2C, the outer cannula 5 comprises ahollow outer tube having a distal end 5A and a proximal end 5B. Fourouter aspiration (i.e., suction) apertures generally indicated byreference numerals 8A, 8B, 8C and 8D are provided on the distal end ofthe inner cannula. As shown, elongated apertures generally indicated byreference numerals 8A, 8B, 8C and 8D are provided on the distal end ofthe inner cannula. As shown, elongated apertures 8A, 8B, 8C and 8Dterminate at a predetermined distance away from outer cannula tip 5C,which is essentially blunt for purposes of safety. In general, thelength of each of these elongated outer apertures is substantiallylonger than the longitudinal extent of each ratio of these lengths isabout 1 to 4 however, in other embodiments, this ratio may differ asdesired or required in a given application. In a typical embodiment, thelength of these elongated outer apertures would be within the range of,for example, two to six inches, commensurate with the amount ofdisplacement to be achieved by each inner aperture.

[0084] As illustrated in FIG. 1B, an outer cannula base 17 extends fromthe proximal end of outer tube 5. The outer cannula base 17 comprises acylindrical structure having a central bore 18, through which distal tip4 and body of inner cannula 4 can freely pass. The outer cannula base 17of the illustrative embodiment includes a flanged portion 19 which fitswithin an annular recess 18 formed in cannula cavity 20 of thehand-holdable housing.

[0085] As shown in FIG. 2B, an inner cannula base 10 extends from theproximal end of inner tube 4. As shown, the inner cannula base 10comprises a cylindrical structure having an outlet port 11 formed in itsremote end. The inner cannula base 10 of the illustrative embodimentincludes a notch or slot 12 formed in its central most portion. As willbe described in greater detail hereinafter, notch 12 functions toreleasably receive an extensional portion 13 of actuation element 37, inorder to actuate reciprocation of inner cannula 4 within housing 2. Asillustrated in FIG. 2B, inner cannula 4 has a continuous passageway 14which extends from inner aspiration opening 9 to outlet port 11. Asshown in FIGS. 2B and 2C, the inner aspiration apertures originatebetween the distal tip portion 4C As shown, elongated apertures 16A,16B, 16C and 16D terminate at a predetermined distance away from outercannula tip 5C, which is essentially blunt for purposes of safety. Ingeneral, the length of each of these elongated inner apertures issubstantially longer than the longitudinal extent of each respectiveouter aperture. In the illustrated embodiment, the ratio of theselengths is about 1 to 4; however, in other embodiments, this ratio maydiffer as desired or required in a given application. In a typicalembodiment, the length of these elongated apertures would be within therange of, for example, two to six inches, commensurate with the amountof displacement to be achieved by each outer aperture with itselectro-cauterizing element.

[0086] While not shown, a conventional vacuum source is connected tooutlet port 11, preferably using optically transparent, semi-flexibletubing 15. With this arrangement, fatty tissue, aspirated fat tissue canbe suctioned through apertures 8A, 8B, 8C and 8D and opening 9 andtransported along passageway 14 to a reservoir device (not shown),operably associated with the vacuum source.

[0087] As illustrated in FIGS. 2A and 2E, electrically-conductivecauterizing electrodes 160A, 160B, 160C and 160D are inserted about theperimeter of outer aspiration apertures 16A, 16B, 16C, and 16D,respectively, and fastened thereto by snap-fitting, adhesive or likemeans. As shown in FIGS. 3A, 3A1, and 3A2, each electrically-conductiveelectrode comprises: a sidewall portion 161 which circumferentiallyextends about the perimeter of the respective aspiration aperture formedin the outer cannula; an opening 162 for permitting aspirated tissue andfat and the like to flow therethrough into the interior of the innercannula; and a circumferential flange 163 substantially perpendicular tosidewall portion 161 and adapted to fit within a recessed groove 164extending about the upper outer surface of the respective outeraspiration aperture formed in the electrically non-conductive outercannula. In the illustrative embodiments, cauterizing electrodes 160Athrough 160D are made from stainless steel, brass, gold or any otherelectrically-conductive material that is suitable for contact with humantissue during liposuction and like surgical procedures.

[0088] As shown in FIG. 2D, the base portion of the outer cannula isprovided with a pair of spaced apart recesses 165A and 165B forreceiving and securing a first and second electrically-conductivecontact pads 166A and 166B, respectively. A first groove 167 is formedwithin the outer surface of the outer cannula 5 and base portion 19 inorder to receive a first length of electrically wiring 168 whichestablishes electrical contact between the set of cauterizing electrodes160A through 160D and an electrically-conductive contact pad 166B.Similarly, a second groove 169 is formed within the outer surface of theouter cannula and base portion 19 in order to receive a second length ofelectrical wiring 170 which establishes electrical contact between theset of cauterizing electrodes 160A through 160D and secondelectrically-conductive contact pad 166A. A sealing material such asmelted plastic can be used to close off the grooves 167 and 169 once theelectrical wiring has been recessed within the groove. Alternatively, athin, outer plastic cannula sleeve having an inner diameter slightlygreater than the outer diameter of outer cannula 4 can be slid thereoverand secured to the base portion thereof 19 using screw-threads, snap-fitfastening, ultrasonic-welding, adhesive or the like. When completelyassembled, electrically-isolated contact pads 166A and 166B are shown inFIG. 2A. It is understood however, that contact elements 166A and 166Bcan be mounted elsewhere in the base portion of the outer cannula.

[0089] As shown in FIG. 2A, an electrically-conductive collar and brushdevice 171 shown in FIGS. 3B and 3B1 is inserted within the central boreformed in the base portion 19 of the electrically non-conductive outercannula. The collar and brush device 171 comprises a cylindrical tube172 made from electrically-conductive material (e.g., stainless steel)having an outer diameter that is slightly less than the diameter of thecentral bore formed through the base portion of the inner cannula. Asshown in FIGS. 3B and 3B1, a pair of diametrically-opposed leaf-likeelectrical contact elements 173A and 173B project inwardly from thecylindrical walls of the device towards its axial center. As best shownin FIG. 2F, the function of electrical contact elements 173A and 173B isto establish electrical contact between second contact pad 166A (on baseportion 10) and electrically conductive inner cannula 4 when the innercannula is slid through the central bore 18 of the outer cannula, asshown in FIG. 2A. A small annular flange 174 is formed on one end of thecylinder 172 to delimit the depth of its insertion. A small connectortab 175 is connected to flange 174.

[0090] As shown in FIG. 2E, the sidewall portion 161 of each cauterizingelectrode 160A through 160D is of sufficient width (w_(g) to provide agap region 175 between (i) the electrically-conductive inner cannula 4adjacent to the electrode and (ii) the sidewall portion 161 thereof.Preferably, the width of each gap 175 is selected so as to minimizeelectrical arcing (i. e. sparking) between each electrode 160 and theelectrically conductive inner cannula 4 when an RF signal of, forexample, about 500 kHZ at 800 Volts is applied thereacross duringelectro-cauterization.

[0091] As shown in FIG. 1B, contact pas 166A and 166B establishelectrical contact with conductive elements 176A and 176B embedded inthe hand-holdable housing and are embedded within recesses formed in thebase portion 19 of the outer cannula assembly. The conductive elements176A and 176B are connected to the RF supply and RF return signalterminals 177A and 177B of RF generator 178. In the preferredembodiment, RF generator 178 is realized as the Instant Response™Electrosurgical Generator (Model Force FX) by ValleyLab International, asubsidiary of Pfizer, Inc. This Electrosurgical Generator can be easilyconnected to the electro-cauterizing electrodes hereof by electricalcabling 179 in order to drive the same with bipolar outputs producedfrom the Electrosurgical Generator. Notably, the Instant Response™Electrosurgical Generator 178 includes three bipolar output modes,namely: Low/Precise; Medium/Standard; and Macrobipolar.

[0092] In order to maintain inner aspiration apertures 8A, 8B, 8C and 8Daligned with outer aspiration apertures 16A, 16B, 16C and 16D,respectively, and thus ensure partial registration therebetween, thedistal end of the inner and outer tubes are provided with a keyingsystem. In the illustrated embodiment, the keying system comprises akeying element 4D disposed on the outer surface of the inner cannula,before distal tip 4C. Keying element 4D can be a rigid or flexibleelement that slides within an elongated outer aperture (e,g, 16B) andprevents axial rotation between cannulas 4 and 5 as they undergorelative reciprocation. To assemble cannula assembly 3, distal tip 4C ofthe inner cannula is inserted through bore 18 in outer cannula base 17so that the distal end of inner cannula 4A is slidably received withinouter cannula 5, as shown in FIG. 3A. In this configuration, keyingelement 4D is received and guided within elongated aperture 8B′ asshown. In this general configuration, cannula assembly 3 is installedwithin cannula cavity 20 by first opening housing cover 21, shown inFIG. 1C. Then outer cannula base flange 17 is inserted within annularrecess 19 and actuation extension 13 within inner cannula base notch 12.Thereafter, housing cover 21 is closed shut and liposuction device 1A isready for operation. A conventional vacuum source is then connected tooutlet port 11, preferably using optically transparent, semi-flexibletubing 15. With this arrangement, fatty tissue, aspirated throughapertures 8A/16B, 8B/16B and 8C/16C and 8D/16D and opening 9, can betransported through passageway 14 to a reservoir device (not shown),operably associated with the vacuum source.

[0093] As shown in FIG. 1A, the gross geometry of housing 2 ispreferably that of an ellipsoid, however, other geometries such as, forexample, a cylindrical structure, can be used in practice in the presentinvention. Housing 2 contains cannula cavity 20, which extends along theentire longitudinal extent of the hand-holdable housing. In theillustrated embodiment, cannula cavity 20 has generally clindricalbearing surfaces 22 which match the outer bearing surface 23 of innercannula base 10, to permit sliding movement of inner cannula 3 withincavity 20. While cylindrical bearing surfaces have been selected in theillustrated embodiment, use of other forms of bearing surfaces (e.g.,rectangular or triangular) are contemplated. To minimize friction,bearing surfaces 22 and 23 may be coated with a Teflon® or functionallyequivalent coating, to facilitate easy slidng of inner cannula base 10within cavity 20 with low wear. As illustrated in FIG. 1B, cannulacavity 20 also includes annular recess 19, into which annular baseflange 19 is adapted to be received in order to render the outer cannulaessentially stationary with respect to hand-holdable housing 2.

[0094] As shown in FIG. 1B, electrical contact pads 176A and 176B areembedded within surface-recesses formed within the wall surfaces of theannular recess 19. Preferably, electrically-conductive contact pads 176Aand 176B are made from electrically conductive material having a shapewhich is similar to the shape of electrically conductive pads 166A and166B that are embedded within the outer surface of the base portion ofthe outer cannula 5. When the cannula assembly of this embodiment isinstalled within the hand-holdable housing, the electrical contact pads166A and 166B on the base portion of the outer cannula willautomatically establish electrical contact with electrical contact pads176A and 176B within recess 19, respectively. in this way, the RF supplyand return voltages from RF signal generator 178 are automaticallyapplied to the electro-cauterizing electrodes embedded within thecannula assembly of the present invention.

[0095] As illustrated in FIG. 1C, hand-holdable housing 2 is providedwith a hinged cover 21. Hinged cover 21 allows cannula cavity 20 to beopened and accessed so that cannula assembly 3 can be selectivelyinstalled in cannula cavity 20 and removed therefrom as desired orrequired. Cover panel 21 has a semi-circular cross-sectional geometryand is connected to the remaining portion of housing 2 by a conventionalhinge means 25. To secure cover panel 21 to the remainder of housing 2,a releasable locking means 26 is provided at the interface of hingecover 21 and housing 2, as shown. Releasable locking means 26 can berealized in a variety of ways, including, for example, using a springbiased clamp element 27 which engages in a notch 28 formed in theexternal surface of the remaining housing portion, as illustrated inFIG. 1C.

[0096] In general, there are numerous ways to effectuate reciprocationof inner cannula 4 within cannula cavity 20 and thus within stationaryouter cannula 5. examples of possible reciprocation means 6 include, butare not limited to, gas or electrically driven motor(s). In theembodiments illustrated in FIGS. 1A through 1C, FIGS. 4A through 6A,FIGS. 7 through 8A, FIGS. 6A through 6D, and FIGS. 10 through 14D, oneor more gas driven piston-type motors are employed to realize thereciprocation means 6 within the liposuction instrument. In theembodiment illustrated in FIGS. 9A through 9F, a rotary-type motor isused to realize reciprocation means 6 of the present invention.

[0097] As illustrated in FIG. 1B, a piston-type motor 6 is mountedwithin a motor cavity 30 provided adjacent cannula cavity 20 of housing2. Notably, this reciprocation means cavity 30 extends essentiallyparallel to cannula cavity 20 and along a substantial portion of thelongitudinal dimension of hand-holdable housing as will become moreapparent hereinafter. This unique spatial relationship between thecannula cavity and reciprocation means cavity within housing 20, ensuresoptional cannula displacement relative to longitudinal dimensions of thehand-holdable housing.

[0098] In general, motor 6 comprises a chamber housing 31 having a gasinlet port 32 and an inner chamber generally indicated by referencenumeral 33. Slidably received within the inner chamber of housing 31 isa movable piston 34 having formed in the lower portion wall 35, one ormore gas outlet ports 36. mounted to the top portion of movable piston34 is actuation element 37, whose extension 13 projects throughlongitudinally disposed sot 38 formed in the bearing wall surface 22 ofcannula cavity 20. As shown in FIG. 1B, actuation extension 13 passingthrough slot 38, is received within notch 12 formed in inner cannulabase 10 and operably associates inner cannula 3 with motor 6.

[0099] As illustrated in FIG. 1B, chamber housing 31 is fixedly disposedwithin motor cavity 30. motor cavity 30 is also provided with at leastone port 39 for ventilating to the ambient environment, gas releasedfrom inner chamber 33 upon movable piston 34 reaching it maximumdisplacement or excursion. Movable piston 34 is biased in the directionof chamber housing 31 by way of a spring biasing element 40. Thecompliance of spring biasing element 40 can be adjusted by moving theposition of slidable wall 41 by rotating, for example threaded element42 passing through a portion 43 of housing 2, as shown. With thisarrangement, adjustment of wall 41, closer to or farther from chamberhousing 31, results in decreasing or increasing, respectively, thecompliance of spring biasing element 40. This mechanism, in turn,provides a simple, yet reliable way in which to control the rate ofreciprocation of movable piston 34, and thus the rate of reciprocationof inner cannula 3 relative to housing 2.

[0100] The manner of operation of piston-type motor 6 is described asfollows. Gas, such as pressurized air or N₂ gas, is introduced underconstant pressure to inlet port 32 of chamber housing 31. As the gasfills up the volume enclosed by the interior walls of movable piston 34and chamber 33, inner chamber 33 begins to expand, forcing movablepiston 34 upwardly against the biasing force of spring biasing element40..When movable piston 34 is displaced sufficiently enough from chamberhousing 31 so that gas within expanding chamber 33 can be releasedthrough gas exit port 39 to the ambient atmosphere, piston 34 will beforced back downwardly into chamber housing 31. The rate of the forceddownward piston movement is inversely proportional to the compliance ofspring biasing element 40. Subsequently, chamber 33 will again fill upwith gas, piston 34 will again be displaced and gas subsequently vented,whereupon reciprocating displacement of piston 34 will be repeated againin a cyclical manner. since movable piston 34 is operably connected withinner cannula base 10 by way of actuation element 37, this reciprocatingmovement of piston 34 results in reciprocating movement of inner cannula3 within cannula cavity 20. Further, this relative reciprocation betweenthe inner cannula and the outer cannula results in periodic displacementof the effective aspiration apertures along the distal end portion ofthe cannula assembly.

[0101] As illustrated in FIG. 1B, the amount of excursion that piston 3is permitted to undergo before gas venting and subsequent downwardpiston movement occurs, is determined by the distance “d” definedbetween gas output port 32 and top wall surface 47 of chamber housing31. A typical cannula excursion distance of about four inches, forexample, will necessitate that the parameter d, defined above, be alsoabout four inches.

[0102] In FIGS. 4A and 4B, a second embodiment of the liposuction deviceof the present invention is shown. Liposuction device 1B has analternative cannula assembly retention means while inhering all of thestructural features of the first embodiment illustrated in FIGS. 1Athrough 1C. In particular, liposuction device 1B does not have ahingedly connected housing cover panel, and instead incorporates asnap-fit type cannula assembly retention mechanism. In accordance withthis embodiment, actuation element 37′ has an extension which isessentially flush with elongated slot 38 formed in cavity wall 22.

[0103] In FIGS. 4A and 4B, an alternative embodiment of theelectro-cauterizing cannula assembly hereof is shown. This cannulaassembly is similar to the above-described cannula assembly in allrespectives except the extension on actuation element 37. In thisalternative embodiment, the extension on actuation 37′ is provided witha spring biased ball bearing 48 that projects slightly beyond cannulacavity wall surface 22. When inner cannula base 10′ is pushed intocannula cavity 20 in the vicinity of actuation element 37′, ball bearing48 engages within indentation ring 49 circumferentially formed aboutinner cannula base 10′. Notable, spring biased ball bearing 48 functionsas an engaging means for inner cannula base 10′.

[0104] As shown in FIG. 4A, the engaging means for outer cannula base17′ is also realized as a spring biased ball bearing 50 installedthrough cannula cavity wall 22. Outer cannula base 5′ is provided withan annular flange 47 and indentation ring 49 circumferentially formedabout outer cannula base 17′. As shown, annular flange 57 establishessurface to surface contact with peripheral surface 58 area of thehousing when cannula base 5′ is pushed into cannula cavity 20. in thisposition, ball bearing 50 engages within indentation ring 49 and asnap-fit engagement is established. This arrangement serves to retainboth inner and outer cannulas 4′ and 4 cannula cavity 20′, in areleasable manner, as actuation element 37′ is caused to reciprocateperiodically. The outer cannula is simply removed from cannula cavity 20by quickly pulling on outer cannula tube 5 with a modest degree offorce, to overcome the bias force of engaged ball bearing 50. Similarly,the inner cannula is simply removed by quickly pulling on inner cannulatube 4′ to overcome bias force of engaged ball bearing 50.Advantageously, this cannula assembly retention mechanism can alsoprovide a safety release feature, in that if inner cannula 4′, forexample, becomes snagged during an operation, it will disengage from thereciprocation means 6 if a proper spring biasing force is selected forball bearing 50.

[0105]FIGS. 7A, 7B and 8 also show an electro-cauterizing cannulaassembly according to the present invention which is adapted for usewith liposuction instruments having cannula retention capabilities ofthe snap-in type described above. Notably, the elements which correspondto inner and outer cannulas illustrated in FIGS. 2A through 3B1, areindicated by similar reference numbers.

[0106] In the embodiment featured in FIGS. 7A and 7B, inner cannula base10″ has a deeply formed spherical indentation 52 which is adapted toreceive ball bearing 48 mounted in the extension of in actuation element37. To facilitate guiding ball bearing 48 into spherical indentation 52,a longitudinally extending groove 53 is formed in inner cannula base10″. Also, as shown, widened recess portions 53A and 53B are provided atopposite ends of groove 53 to facilitate initial insertion of ballbearing 48 in groove 53. When inner cannula base 10″ is slid intocannula cavity 20, ball bearing 48 snaps into indentation 52 toestablish a locked position. Biased ball bearing 48 engaged in sphericalindentation 52 serves to retain inner cannula 5 within cannula cavity20, while facilitating reciprocation of inner cannula 5 when actuationelement 37′ is caused to reciprocate.

[0107] Similar to the snap-fit inner cannula retention mechanismillustrated in FIGS. 7A and 7B, FIG. 8 shows outer cannula base 17″having a longitudinally extending groove 55. Also, as shown, widenedrecess portions 55A and 55B are formed at opposite ends of groove 55 tofacilitate insertion of ball bearing 50 into spherical indentation 56.When outer cannula base 17″ is slid into cannula cavity 20, ball bearing50 snaps into spherical indentation 56 to establish a locked position.When this occurs, annular flange 57 will engage with outer peripheralsurface 58, about circular access opening leading into cannula cavity,shown in FIG. 4A. Upon such engagement, outer cannula 5 is renderedstationary relative to hand-holdable housing 2. As with inner cannula 4,the outer cannula is simply removed from cannula cavity 20 by pulling onouter cannula tube 5 with a modest degree of force to overcome the biasforce of engaged ball bearing 50.

[0108] In order to selectively adjust the amount of cannula excursionpermitted during a liposuction operation, piston-type motor 6 can bemodified, as shown in FIG. 5, to produce a third embodiment of theliposuction device of the present invention. As illustrated in FIG. 5,the basic structure of liposuction device 1C is similar to that shown inFIGS. 1A through 1C, except that a user-adjustable intermediate housingwall 88 is disposed between the inner walls 31A of chamber housing 31and the outer walls 34A of movable piston 34. Intermediate housing wall87 is operably associated with an excursion selection means realized asa slidable member 88 fixedly attached to the upper portion ofintermediate housing wall 59. Preferably, slidable member 88 extendsthrough a slot 89 formed in the wall of housing 2 and can be slid, forexample, by movement of the surgeon's thumb. The function ofintermediate housing wall 87 is to effectively raise the height of thechamber housing wall, and thus selectively increase distance d, defined,for example, as the distance between gas outlet port 32 in piston 34 andupper portion 63 of the chamber housing wall. In this way, movablepiston 34 must undergo a larger displacement before compressed gas willbe released and piston 34 permitted to be forced downwardly under thebiasing force of biasing spring element 40.

[0109] As illustrated in the embodiment shown in FIG. 5, it is alsopossible to control the rate of reciprocation of the inner cannula bycontrolling the rate of gas flow entering chamber 33 of piston-typemotor 6. This can be achieved using a conventional gas flow regulationdevice 78 inserted between source of gas “S” and inlet port 32 ofchamber housing 31. As shown, tubing sections 79A and 79B are used toachieve fluid communication between these elements. Typically, cannulareciprocation rates will be in the range of 30 to 90 reciprocationcycles per minute, and the corresponding gas flow rates will depend onparameters including, for example, the compliance of biasing spring 40,the volumes of movable piston 34 and chamber housing 31, thecross-sectional diameter of gas inlet port 32, and the cross-sectionaldiameter of gas outlet ports 36 in the piston.

[0110] Referring to FIGS. 6A through 6D, there is shown anotherembodiment of the liposuction device of the present invention. Inliposuction device IF, the housing and cannula assembly are generallysimilar to those of the previously described embodiments, with theexception of several differences which will be described below.

[0111] As illustrated in FIG. 6A, a pair of piston-type motors 6A and 6Bof the type generally indicated in FIGS. 1A through 1C and 5, arefixedly installed within respective motor cavities 30A and 30B ofhousing 2. Each piston-type motor 6A and 6B has a respective chamberhousing and movable piston, indicated by 31A and 31B, and 34A and 34B,respectively. Actuation elements 37A and 37B are fixedly connected torespective pistons 34A and 34B and project through respective elongatedslots 38A and 38B formed in cannula cavity wall 22; this is achieved, ina manner similar to that described in connection with the embodimentsshown in FIGS. 1A through 1C, 4A, 4B and 5. While not shown in FIG. 6A,preferably a rod or bar is fixedly attached between actuation elements37A and 37B in order to maintain them a fixed distance apart, and yetprovide an operable connection between the inner cannula 4 ¹ andactuation elements 37A and 37B in the manner described below. As shownin FIG. 6B, this embodiment includes hinged cover panel 21 in a mannersimilar to that described in the embodiments of FIGS. 1A, 1C, 5, 6A and8A.

[0112] As illustrated in FIG. 6A, inner cannula base 10′″ has first andsecond receiving slots or notches 12A and 12B, into which extensions 13Aand 13B of respective actuation elements 37A and 37B are received. Suchoperable connections between movable pistons 6A and 6B and inner cannulabase 10′″ enables inner cannula 4′ to reciprocate relative to housing 2when actuation elements 37A and 37B are caused to reciprocate relativeto respective gas driven motors 6A and 6B.

[0113] In order to control the filling and venting of chambers 33A and33B of the first and second piston motors, to effectuate cyclicalreciprocating motion of actuation elements 37A and 37B and thus innercannula 4′, a mechanically-operated gas flow control device 90 isprovided. As shown in FIG. 6A, gas flow control device 90 is employed inoperable association with an external source of pressurized gas (notshown), gas inlet ports 32A and 32B, and movable pistons 34A and 34B.

[0114] As illustrated in greater detail in FIGS. 6C and 6D, gas flowcontrol device 90 comprises a shuttle valve housing or casing 91, havingfirst and second shuttle chambers 92A and 92B. These shuttle chambersare separated by a shuttle valve member 93 which is fixedly attached toa slidable shaft 94. As illustrated, shuttle valve member 93 is slidablebetween two positions or states “A” and “B”. In order to achieve thisshaft 94 extends through bores 95A and 95B formed in shuttle chamber endwalls 91A and 91B respectively, in which seals 96A and 96B are installedin a conventional manner. When the shuttle valve 93 is centrallydisposed in casing 91 between states A and B, shaft ends 94A and 94Bprotrude equally beyond respective bores 95A and 95B.

[0115] Adjacent one end of the cylindrical shuttle chamber side wall 98,a first gas exit port 89A is formed, whereas adjacent the other end ofwall 98, a second gas exit port 98B is formed, as shown. At aboutintermediate the end walls, a gas inlet port 100 is formed in shuttlechamber side wall 98. A pair of annulus-shaped shuttle valve stops 101Aand 101B are formed at opposite end portions of the interior surface ofcylindrical wall 98. These stops 101A and 101B serve to limit slidingmovement of shuttle valve 93 when shaft 94 is displaced in one of twopossible axial directions by actuation elements 37A and 37B,respectively, as shown in FIG. 6A. As will be discussed in greaterdetail hereinafter, it is these actuation elements 37A and 37B whichdisplace shaft 94 and thus shuttle valve 93 between one of two states,as movable pistons 34A and 34B are caused to reciprocate. Preferably, atleast a portion of shuttle valve 93 is formed of a ferromagneticmaterial so that ferrous end walls 102A and 102B will attractferromagnetic shuttle valve 93 and pull it against one of stops 101A and101B and into gas flow state A or B, i.e., when shuttle valve 93 isbrought into proximity therewith upon displacement of shaft 94 by one ofactuation elements 37A and 37B. Peripheral side surfaces of shuttlevalve 93 are provided with seals 103 to prevent gas leakage betweenshuttle chambers 92A and 92B.

[0116] As illustrated in FIG. 6A, first gas exit port 99A of device 90is in fluid communication with second chamber housing 31 B by gaschannel 104, whereas second gas exit port 99B is in fluid communicationwith first chamber housing 31A by gas channel 105. In the illustratedembodiment, gas inlet aperture 106 is formed through housing 2 andpermits gas channel 107 to establish fluid communication between gasinlet port 100 and the external source of pressurized gas. Notably,chamber housings 31A and 31B, shuttle valve housing 91, gas channels104, 105 and 107 can be realized as discrete elements, as shown, oralternative as integrally formed elements which are part of the interiorof the hand-holdable housing itself.

[0117] The principal function of gas flow control device 90 is tocontrol the flow of gas to pistons 34A and 34B so that only one of thegas pistons is actively driven at a time, while the other is passivelydriven. The manner of operation of gas flow control device 90 incooperation with the periodic displacement of pistons 34A and 34B, willnow be described.

[0118] Owing to the fact that shuttle valve 93 is magnetically biased tobe in essentially one of two possible positions, or gas flow states, gaswill initially be caused to flow into one of piston-chamber housings 31Aor 31B, and cause its respective piston and actuation element to moveaway (i.e., protract) from its respective chamber housing. Only along asmall portion of the piston excursion will shuttle valve shaft 94 andthus shuttle valve 93, be displaced within shuttle valve housing 91 asthe actively driven piston is displaced upon buildup of pressurized gaswithin its respective chamber.

[0119] To illustrate this cyclical process, it will be assumed that gasflow control valve 90 is initially in state A, as shown in FIG. 6A.Here, piston 34A has reached its maximal displacement and pressurizedgas within chamber 33A has been substantially vented through gas outletport 26A and through ports 39A and 39B. In this position (state A),shuttle valve 90 is magnetically biased against stops 101B so that gasis caused to flow from the external gas source (not shown), throughfirst shuttle chamber 92A and into second chamber housing 33B. Withshuttle valve 93 in this state, gas pressure is allowed to build up inchamber 33B, displacing piston 34B and actuation element 37B to protractfrom second chamber housing 31B. Therewhile, inner cannula base 10′″ iscaused to undergo an outwardly directed excursion within cannula cavity20, commensurate with the active displacement of piston 34B. Duringpiston excursion (i.e., travel) defined over length L₁, shuttle valve 93remains in stage A against stop 101B.

[0120] Then over piston excursion L₂, actuation element 37B contactsshaft end 94B and displaces shuttle valve 93 away from stop 101B toabout mid-position in shuttle housing 91, approximately over input port100, at which point, magnetic shuttle valve 93 is pulled toward ferrousplate 102A into state B and against stop 101A, as shown in FIG. 6A withphantom lines. At this phase in the cycle, piston 34A is fully retractedwithin chamber housing 31A, while piston 34B is fully protracted fromchamber housing 31B and displaced a distance L₃ from the upper portionthereof (i.e., L₃=L₁+L₂). In State B, gas flow control device 90 directsthe flow of pressurized gas from the external source, along channel 107,through second shuttle chamber 92B and along channel 105 and into pistonchamber housing 31A.

[0121] Magnetically biased shuttle valve 93 remains in state B aschamber housing 31A fills with pressurized gas, expanding the chamber33A and actively displacing piston 34A away from chamber housing 31A,while causing piston 34B to passively retract back into its chamberhousing 31B. All the while, inner cannula base 10′″, being operablyassociated with actuation elements 37A and 37B, undergoes a commensurateamount of inwardly directed excursion within cannula cavity 20. Whenpiston 34B is displaced an amount of distance L₄, actuation element 37Acontacts shaft end 94A and displaces shuttle valve 93 a small distanceL5, at which point, magnetic shuttle valve 93 is pulled towards ferrousplate 102B, back into state A and against stop 101B. At this phase inthe cycle, piston 34B is fully retracted within chamber housing 31 whilepiston 34A is fully protracted within chamber housing 31A and displacedat a distance L₆ from the upper portion thereof (i.e., L₆=L₄+L₅). Instate A, gas flow control device 90 directs the flow of pressurized gasfrom the external source, along channel 107, through first shuttlechamber 92A, along channel 104 and into piston chamber housing 31B.

[0122] Magnetically biased shuttle valve 93 remains in state A aschamber housing 91B fills with pressurized gas, expanding chamber 3Bactively displacing piston 34B away from chamber housing 31B, whilecausing piston 34A to passively retract back into its piston chamberhousing 31A. All the while, inner cannula base 10′″, being operablyassociated with actuation elements 37A and 37B, undergoes once again acommensurate amount of outwardly directed excursion within cannulacavity 20. With a preselected gas pressure and flow rate set at gasinlet port 100 of device 90, the above-described process of gas filling,venting and flow control occurs automatically at a corresponding rate,resulting in periodic reciprocation of inner cannula 10′″ relative tohand-holdable housing 2. In turn, this periodic reciprocation of innercannula 4′ results in periodic displacement of the general location ofaspiration occurring along the length of the cannula assembly.

[0123] Referring to FIGS. 9A through 9F, there is illustrated yet aseventh embodiment of the liposuction device of the present invention.In general, liposuction device 1G has a pistol-shaped housing 110 whichcomprises a barrel portion 111 and a detachable handle portion 112.Instead of using a reciprocating piston motor to translate inner cannula4′ relative to housing 100, this embodiment utilizes a rotary-type motor113. In operative association with a cam mechanism, generally indicatedby reference numeral 114, rotary-type motor 113 causes actuation element115 to cyclically slide back and forth and cause inner cannula 4′ toperiodically reciprocate relative to barrel portion 111 of thepistol-shaping housing.

[0124] As illustrated in FIGS. 9B through 9D, barrel portion 111 of thehousing comprises a cannula cavity 116 adapted for slidably receivingcylindrically-shaped base 17 of inner cannula 4′, in a manner describedhereinabove. Cannula cavity 116 is also provided with a longitudinallyextending access opening, over which a hingedly connected cover panel117 is provided. As illustrated in FIG. 9E, cover panel 117 facilitatesinsertion of the cannula assembly into, and removal of the cannulaassembly from, cannula cavity 116 in a manner similar to that describedin connection with liposuction instrument 1A of FIGS. 1A through 1C, inparticular. As illustrated in FIG. 9C in greater detail, inner cannulabase 10 is adapted to be received within cannula cavity 116 and outercannula base flange 19 releasably received with annular recess 118formed in cannula cavity wall 22.

[0125] To install inner cannula 4′ into cannula cavity 116,semi-flexible transparent tubing 15 is connected to inner cannula outletport 11. Then cover panel 117 is opened and tubing 15 fed out throughrear port 119 of the barrel portion, as illustrated in FIGS. 9C and 9F.Inner cannula base 10 is then slid into cavity 116 with extensionalportion of actuation element 115 received in notch 12. Then outercannula 5′ is slid over the distal end of inner cannula 4′ until outercannula base 17 is received within annular recess 118. Thereafter, asshown in FIG. 9E, cover panel 117 is snapped closed using, for example,a spring biased locking device 120, of the type previously describedabove. Removal of inner and outer cannulas simply involves a reversal ofthe above procedure.

[0126] Alternatively, using spring biased actuation elements and innerand outer cannulas of the type shown in FIGS. 4A and 4B, barrel portion111 can be realized without necessity of hinged cover panel 117. In suchan alternative embodiment, the inner and outer cannulas can besnap-fitted into and pulled out of cannula cavity 116 in a mannersimilar to that described hereinabove.

[0127] As illustrated in FIGS. 9B through 9F, barrel portion 111 housescam mechanism 114 which is operably associated with (i) rotary motor 113contained within the handle portion, and (ii) actuation element 115which slidably passes through a longitudinal slot 121 formed within theupper wall of cannula cavity 116. As in the other previously describedembodiments, actuation element 115 includes extension 115A that passesthrough elongated slot 121 and is received within notch 12 formed ininner cannula base 10. In addition, cam mechanism 114 of the illustratedembodiment inherently embodies gear reduction. In this way, a highangular shaft velocity of rotary motor 113, can be efficientlytransformed into reciprocational strokes of the cannula, occurring at asubstantially lower rate. With such an arrangement, as rotary motor 113is caused to rotate under either gas pressure or electrical power,actuation element 115 is caused to reciprocate within elongated slot 121by way of cam mechanism 114, and thereby cause inner cannula 4′ toperiodically reciprocate relative to housing 110. This motion results inperiodic displacement of the general location of aspiration occurringalong the length of the cannula assembly.

[0128] As illustrated in FIGS. 9B and 9C, cam mechanism 114 of thepreferred embodiment comprises a drive wheel 122 having a firstpredetermined number of gear teeth 123 disposed thereabout. Drive wheel122 is rotatably mounted to a shaft 124 mounted through and opening inthe top panel of an accommodating section 125 of the barrel portion. Cammechanism 114 also includes a connective element 126 having first andsecond ends 126A and 126B, respectively. First end 126A of theconnective element in pivotally attached to the drive wheel 122 at apoint posed away from the axial center 124, whereas second end 126B ispivotally connected to actuation element 115 as shown. In order toadjust the distance away from the axis of rotation 124 at which thefirst end of the connective element is pivotally attached, a radiallyformed slot 127 is formed in drive wheel 122. A plurality of widenedcircular apertures 128 are disposed along radial slot 127 as shown inFIGS. 9B and 9D. In this way, a spring-loaded cylindrical pin 129passing through the first end of connective element 126, can beselectively locked into one of apertures 128 by pulling upwardly uponpin 129 and setting its cylindrical base 129A into the desired aperture128. In FIG. 9D, pin 129 is shown to further include pin head 129B, ahollow bore 129B, and an axle 129D having heads 129E and 129F. As shown,a spring 129G in enclosed within bore 129C, about axle 129D and betweenhead 129F and an inner flange 129H. By selectively locking the first end126A of connective element 126 into a particular circular notch 128using spring loaded pin 129, the distance of the first end of theconnective element from axial center 124 can be set, and thus the amountof inner cannula excursion (and effective aspiration aperturedisplacement) thereby selected. To permit access to spring-loaded pin129, the top panel of accommodating portion 125 of the housing isprovided with hinged door 132 that can be opened and snapped closed asdesired.

[0129] As illustrated in FIGS. 9B and 9C, handle portion 112 of thehousing encloses a substantial portion of rotary motor 113 whose shaft133 projects beyond the handle portion and bears a gear wheel 134. Asshown, gear wheel 134 has a second predetermined number of gear teeth134A disposed circumferentially thereabout, which mesh with drive wheelteeth 123. notably, to permit the rear portion 119 of cannula cavity 116to extend all the way towards the rear of the barrel portion for passageand exit of aspiration hose 15, shaft 133 of the motor is mounted offcenter of handle portion 113, as shown in FIGS. 9C and 9F.

[0130] Rotary motor 113 is preferably an electric motor whose shaftspeed is controllable by the voltage applied to its terminals. Suchspeed control can be realized by a conventional speed control circuit135 connected between motor 113 and a conventional 110-115 volt, 50-60Hertz power supply. As illustrated in FIG. 9C, conventional electricalcord 136 and on/off power switch 150 can be used to connect controlcircuit 135 and the power supply. Control over the output voltageproduced from speed control circuit 115 and provided to electrical motor113, can be adjusted, for example, by changing the resistance of apotentiometer 137 which is operably connected to the speed controlcircuit. As shown in FIG. 6C in particular, this potentiometer 137 canbe embodied within a trigger mechanism 138 which is connected, forexample, to handle portion 112 of the housing 110. By pulling trigger138, the speed of rotary motor 113 can be controlled, and consequently,so too the rate of reciprocation of inner cannula 4′ relative to outercannula 5′, and thus the rate of displacement of the effectiveaspiration apertures.

[0131] To connect handle portion 112 to barrel portion 111 and permitdisconnection therebetween for cleaning, sterilization and generalservice, handle portion 112 is provided with flange 140 and thumboperable spring element 141. Barrel portion 111, on the other hand, isprovided with slot 142, catch 143, and cavity 144. To connect handleportion 112 to barrel portion 111, shaft 133 is vertically passedthrough channels 144 and 145 until gear 134 is slightly below the planeof drive wheel 122. Then, spring element 141 is inserted within cavity144 while flange 140 is guided into slot 142. By pushing the rearportion of handle 112 in the longitudinal direction of cannula cavity116, spring element 141 will snap over and clasp catch 143 as shown inFIG. 12C. In this configuration, handle portion 112 is secured to barrelportion 111 and gear teeth 123 will mesh with drive wheel teeth 134A. Todisconnect handle portion 112 from barrel portion 11, the surgeon'sthumb simply depresses spring-element 141 downwardly and then, by movinghandle portion 112 slightly rearwardly, then downwardly, flange 140 isdislodged from slot 142 and motor shaft 133 can be withdrawn fromchannels 144 and 145. In this disassembled state, handle portion 110 andbarrel portion 112 can be individually cleaned and sterilized usingconventional procedures known in the surgical instrument art.

[0132] Liposuction device 1G described above employed an electricalrotary motor to effectuate reciprocation of inner cannula 4′ relative tohousing 110. However, in an alternative embodiment, it is possible toeffect reciprocation of the outer cannula while the inner cannula isstationary with respect to the housing, as shown in FIGS. 6A through 7.Also, it is possible to employ a conventional gas driven rotary motor inlieu of electric rotary motor 113. In such an embodiment, trigger 138can be operatively associated with a gas flow control valve. Thus, bycontrolling the rate of gas flow to the gas rotary motor upon actuationof trigger 138, the angular velocity of shaft 133 can be controlled andthus the rate of reciprocation of inner cannula 4′ relative to housing110.

[0133] Having described various illustrated embodiments, it isappropriate at this juncture to describe the method of the presentinvention using, for purposes of illustration only, the liposuctioninstrument 1C illustrated in FIG. 5.

[0134] In general, the surgeon prepares in a conventional manner, thearea of skin below which liposuction is to be performed. Typically, thisentails marking various zones where radial displacement of theaspiration apertures are to occur. Liposuction instrument 1C of thepresent invention is assembled as described above so that aspirationapertures 8A′, 8B′ and 8C′ of cannula assembly 3′ are in communicationwith a vacuum source (not shown). A small incision is then made in thepatient's skin in a conventional manner, and the distal portion of thecannula assembly is inserted into a premarked radial zone. Aspressurized gas is provided to piston motor 6, inner cannula 10 willautomatically reciprocate causing the general location of the suctionapertures to be automatically displaced along each tunnel of fattytissue. During the operation of the instrument, the surgeon's handholding the liposuction instrument is maintained essentially stationarywith respect to the patient. Fatty tissue is aspirated through theperiodically displaced aspiration apertures, and transferred into areservoir tank operably associated with the vacuum source.

[0135] As deemed necessary, the surgeon can selectively increase therate of aspiration aperture travel along the distal end of the cannulaassembly. This can be achieved by a foot-operated gas flow controldevice 78 which controls the rate of gas flow to piston motor 6. Also,the amount of inner cannula excursion (i.e., aspiration aperture travel)can also be selected by adjusting the compliance of spring 40 throughrotation of threaded element 42.

[0136] In the illustrative embodiments described hereinabove, the outercannula has been made from an electrically non-conductive material(i.e., achieving electrical isolation between the cauterizing electrodessupported on the outer cannula, and electrically conductive innercannula). The inner cannula ha been made from stainless steel, offeringthe advantage of being easily cleaned and sterilizable. The plasticouter cannula offers the advantage of electrical insulation, lowmanufacturing cost and disposability. Preferably, when making the outercannula from a suitable plastic material, injection molding processescan be used.

[0137] In FIG. 10, an alternative embodiment of the liposuctioninstrument of FIG. 9 is shown. While this embodiment of liposuctioninstrument hereof 180 is similar to the embodiment shown in FIG. 9,there are a number of differences. For example, an actuator 181magnetically-coupled to an air powered cylinder 182 is used toreciprocate the base portion 10 of the inner cannula of itselectro-cauterizing cannula assembly. The magnetically-coupled airpowered cylinder and actuator subassembly (182, 181) can be realized asModel No. MG 038 commercially available from Tol-O-Matic, Inc. of Hamel,Minn. As shown in FIG. 10, the ends of the air powered cylinder 182 aresupported by an external guide and support system comprises brackets183A and 183B, which are integrated with interior portions of thehand-holdable housing. The actuator block 181, which is mounted aboutthe cylindrical shaft of the cylinder 182, reciprocated between thesupport brackets 183A and 183B in response to pressurized air (gas)flowing into its first air input/output port 184A, then the second airinput/output port 184B, repeatedly in an alternating manner, causing theactuator 181 to reciprocate along the cylinder 182. Such pressurized airstreams are provided by an air-flow control device 185.

[0138] As shown in FIG. 10A, the air flow control device 185 has one airsupply port 185A, first and second air output/return ports 185B and185C, and first and second air exhaust ports 185D and 185E. Air supplyport 185A is supplied with pressurized air through tubing 185A1connected to flow rate control unit 219 which is controlled byelectrical signals produced by trigger 138 when pulled to a particulardegree of angular function of deflection. The control unit 219 is tocontrol the flow of air from supply tubing section 219A connected to anexternal source of pressurized air. The first and second airoutput/return ports 185B and 185C, are arranged in fluid communicationwith the first and second air input/output ports 184A and 184B of thecylinder 182, respectively, by way of air tubing sections 186 and 187.

[0139] As shown in FIG. 10A, air-flow control device 185 has an air flowcontrol shaft 188 with air flow directing surfaces 188A. Air flowcontrol shaft is slidably supported within the housing of the device.The function of the flow control shaft is to commute air flow betweenits various ports described above in response to the position of theactuator 181 along the cylinder 182 during device operation. In order toachieve such functions, the air-flow control shaft 188 of theillustrative embodiment is mechanically coupled to an actuator strokecontrol rod 189 by way of a mechanical linkage 190. Linkage 190 issupported by brackets 191A, 191B and 191C and secured to the interior ofthe hand-holdable housing. Along the actuator stroke control rod 189, apair of actuator stops 192A and 192B are disposed. In the illustrativeembodiment, stops 192A and 192B are disposed. In the illustrativeembodiment, stops 192A and 192B are realized as slidable rods which areadapted to lock into different detented positions along the strokecontrol rod 189 when the surgeon presses the top thereof (locatedoutside of the housing) downwardly and then in the direction of theadjustment, releasing the control stop at its desired location. In someembodiments, in may be desirable to fix on eof the control stops whileallowing the other control stop to be adjustable along a selectedportion of the length of the stroke control road 189. In alternativeembodiments, actuator stroke control can be realized using other typesof adjustment mechanism including, or example, externally accessibleadjustment screw mechanism, in which adjustment (rotation) of a singleknob or thumb0wheel enables the surgeon to set the stroke length of theinner cannula and thus the aspiration aperture thereof, electroniccontrol mechanisms, in which actuation of an electronic or electricaldevice, such as foot pad or electrical switch enables the surgeon totranslate the position of one or both of the stroke control stops byelectro-mechanical means (including linear motors, geared rotary motorsand the like).

[0140] As shown in FIG. 10A, the air flow control shaft 188 has twoprimary positions; a first position, in which pressurized air from theair supply port 185A is directed to flow through the second airoutput/return port 188C of the air flow control device, along tubing 187and into the second input/output port 184B of the cylinder 182, whilethe second input/outlet port 184B of the cylinder is in communicationwith the first exhaust port 185D of the air flow control device 185causing inner cannula to project away from the housing; and a secondposition, in which pressurized air from the air supply port 185A isdirected to flow through the first air output/return port 188B of theair flow control device, along tubing 186 and into the firstinput/output port 184A of the cylinder, while the second input/outletport 184B of the cylinder is in communication with the second exhaustport 185E of the air flow control device 185, causing the inner cannulato retract inwards towards the housing. By virtue of this arrangement,the actuator 181 is automatically driven back and forth between strokecontrol stops 192A and 192B along the cylinder stroke rod in response topressurized air flow into the air flow control device 185. When theelectro-cauterizing cannula assembly of FIG. 11A is installed within thecannula cavity of the liposuction device, as described hereinabove, theinner cannula 4 will be caused to reciprocate relative to the outercannula 5. In the illustrative embodiment, the length of the excursionof the inner cannula 4 is determined by the physical spacing betweenmechanical stops 192A and 192B. By varying the spacing of these stopsalong the stroke control rod 182, the maximum excursion of the innercannula relative to the stationary outer cannula can be simply andeasily set and reset as necessary by the surgeon.

[0141] In FIG. 11A, an electro-cauterizing cannula assembly 3″ is shownfor use with the liposuction instrument of FIG. 10. In this illustrativeembodiment, both the inner and outer cannulas are made of anelectrically non-conductive material such as sterilizable plastic. Inthe embodiment of FIG. 10, hand-holdable housing is preferably made froman electrically nonconductive material. Electrically conductiveelectrodes 195A, 195B, 195C an 195D are inserted within the inneraspiration apertures 8A, 8B, 8C and 8D, and electrical wiring 196 run tothe inner cannula base portion 10, wherein an electrical contact pad 197is embedded. Electrically conductive electrodes 160A, 160B, 160C and160D are also inserted within the outer aspiration apertures 16A, 16B,16C and 16D, and electrical wiring 168 run to the outer cannula baseportion 19, wherein an electrical contact pad 166B is embedded. Anelectrical contact pad 176B is also embedded within the base portionrecess within the hand-holdable housing.

[0142] As shown in FIGS. 10 and 11, an electrical contact rail 198 isembedded within the side wall surface of the cannula cavity so thatelectrical contact pad 197 on base portion 10 of the inner cannulaestablishes electrical contact therewith to apply RF (supply/return)power signals to the electrodes in the inner cannula during liposuctionoperations. In such circumstances, two sets of electrical connectionsoccur. Firstly, the base portion 10 of the inner cannula is securelyengaged by the actuator block 181 (snap-fitting or other suitable means)and the electrical contact pad 197 contact with the electrical rail 198embedded within the inner side wall surface of the cannula cavity.Secondly, the base portion 19 of the outer cannula is received withinthe base portion recess of the hand-holdable housing and the electricalcontact pad (i.e., RF power supply terminal) 176B embedded therewithinestablishes contact with the electrical contact 166B embedded within thebase portion of the outer cannula. By virtue of these electricalconnections, RF supply potentials are applied to the electrode portionsof the inner cannula, while RF return potentials are applied to theelectrode portions of the outer cannula, whereby electro-cauterizationoccurs.

[0143] In FIG. 13A through 13D, an alternative electro-cauterizingcannula assembly 3′″ is shown for use with the liposuction instrumentshown in FIGS. 10 and 10A, and readily adaptable for use with otherliposuction instruments of the present invention. In this particularillustrative embodiment, both the inner and outer cannulas are made ofan electrically conductive material. The hand-holdable housing is madefrom an electrically non-conductive material (e.g. plastic). Betweenthese electrically non-conductive cannulas 4 and 5 means are providedfor maintaining electrical isolation between the electrically conductivecarrier and outer cannula which, during electro-cauterization, aremaintained at an electrical potential difference (i.e., voltage) of 800volts or more. In general, a variety of different techniques can beemployed for carrying out this functionality. For example, a thincoating of Teflon® material 200 can be applied to the outer surface ofthe inner cannula, and/or to the inner surface of the outer cannula.Alternatively, a series of electrically-insulating spacer/washers madefrom Teflon® ceramic, or like material can be mounted withincircumferentially extending grooves formed periodically about the innercannula to maintain sufficient spacing and thus electrical insulationbetween the inner and outer cannulas. Preferably, the spacing betweeneach pair of insulating spacers is smaller than the length of the bore18 formed in the electrically conductive base portion of the outercannula, as illustrated in FIG. 13A.

[0144] As shown in FIG. 11G, electrical contact rail (i.e. RF powersupply terminal) 198 embedded within the cannula cavity establisheselectrical contact with the base portion 10 of the inner cannula whenthe cannula assembly is installed in the housing of the device. Also,electrical contact pad 176B embedded within the recess portion of thehousing establishes electrical contact with the base portion of theouter cannula when the cannula assembly is installed within thehand-holdable housing. In the assembled state, two sets of electricalconnections occur. Firstly, the electrically conductive base portion ofthe inner cannula is engaged by the electrical contact rail 198.Secondly, the base portion of the outer cannula is received within thebase portion recess and the base portion of the outer cannulaestablishes contact with the electrical contact 176B embedded within therecess portion. By virtue of these electrical connections, RF supplypotentials are applied to the inner cannula, while RF return potentialsare applied to the outer cannula. The potential difference(s) betweenthese surfaces about the aspiration apertures enableelectro-cauterization of tissue as it is being aspirated through theaspiration aperture moving along the cannula assembly.

[0145] In another illustrative embodiment of the present invention, theinner cannula 4 is made of an electrically non-conductive material suchas plastic. The outer cannula is made of electrically conductivematerial (e.g., stainless steel). The hand-holdable housing is made froman electrically non-conductive material (e.g., plastic). Electricallyconductive electrodes are inserted within the inner aspiration aperturesthereof, and electrical wiring run to the inner cannula base portion,wherein an electrical contact rail is also embedded.

[0146] As shown in FIG. 14G, an electrical contact rail 213A is alsoembedded within the side wall of the cannula cavity. An electricalcontact pad embedded within the recess of the plastic hand-holdablehousing establishes electrical contact with the base portion of theelectrically conductive outer cannula. Thus, when the cannula assemblyis installed within the hand-holdable housing, two sets of electricalconnections occur. Firstly, the base portion of the inner cannula isengaged by the actuation means and the electrical contact padtherewithin establish contact with the electrical contacts embeddedwithin the base portion of the inner cannula. Secondly the base portionof the outer cannula is received within the base portion recess and theelectrical contact pads embedded therewithin establish contact with theelectrical contact embedded within the base portion of the outercannula. By virtue of these electrical connections, RF supply potentialsare applied to the electrode portions of the inner cannula, while RFreturn potentials are applied to the electrode portions of the outercannula.

[0147] In yet other alternative embodiments of the present invention,hemostasis can be carried out in the powered liposuction instrumentshereof by producing ultrasonic energy (having a frequency of about 50kilohertz) and delivering the same to the aspiration aperture regions ofthe cannula assembly during liposuction procedures. Such ultrasonicenergy will cause protein coagulation of aspirated tissue in the regionsof the aspiration apertures;. When the frequency of the ultrasonicenergy is reduced to about 20-25 kilohertz, liquefaction or lipolysis ofthe aspirated tissue will occur. Such modes of operation can be added toany of the electro-cauterizing liposuction instruments of the presentinvention, or two liposuction instruments with electro-cauterizingcapabilities.

[0148] In FIGS. 14 through 14C, a preferred embodiment of the ultrasoniccauterizing liposuction instruments of the present invention is shown.In general, the embodiment shown in FIGS. 114 through 14C is similar tothe liposuction instrument of FIG. 10, except that it includes severaladditional means which enable it to effect protein coagulation (and thushemostasis) during liposuction using ultrasonic energy having afrequency of about 50 kilohertz and sufficient power. As shown, a set ofpiezo-electric crystals 210 are embedded about the lumen of the innercannula and encased within the base portion of the inner cannula made ofplastic.

[0149] As shown in FIG. 1, an electrical signal generator 216 externalto the liposuction device is provided for supplying electrical drivesignals to terminals 214 via control circuit 215 when it is enabled bymanual actuation of trigger 138. the electrical signal generator 216should be capable of producing electrical signals having a frequency inthe range of about 15 to 60 KHz, at a sufficient power level. Anycommercially available signal generator, used in medical applications,can be used to realize this system component. The electrical signalsproduced from generator 216 are applied to the terminals of thepiezo-electric transducers embedded within the electricallynon-conductive base portion of the inner cannula.

[0150] When the generator 216 is switched to produce signals in rangecentered about 20 KHz, these signals are delivered to the array ofpiezo-electric transducers embedded within the base portion of the innercannula. These drive signals cause the piezo-electric transducers toproduce ultrasonic signals in substantially the same frequency range topropagate along the surface of the inner cannula and out the inner andouter aspiration apertures, enabling lipolysis or liquefaction ofaspirated fat tissue.

[0151] When the generator is switched to produce signals in rangecentered about 50 KHz, these signals are delivered to the array ofpiezo-electric transducers embedded within the base portion of the innercannula. These drive signals cause the piezo-electric transducers toproduce ultrasonic signals in substantially the same frequency range toestablish standing waves within the inner cannula which propagate outthe apertures of inner and outer cannula, enabling coagulation ofprotein molecules within aspirated tissue, thus achieve hemostasis.

[0152] While carrying out lipolysis using ultrasonic energy producingmeans within the liposuction device hereof, the surgeon may also desireto conduct hemostasis by coagulating protein molecules within tissuebeing aspirated. As shown in FIG. 14, by pulling trigger 138, controlcircuit 217 automatically commutes RF supply and return signals from theRF signal supply unit 175 to power supply terminals 218 which, in turn,are connected to contact pads 176A and 176B embedded within recess 17A,supporting the base portion of the outer cannula with respect to thehand-holdable housing.

[0153] As shown in FIGS. 10 and 14, a flow control switch 219 isprovided within the handle of the housing in order to enable the flow ofpressurized air from air supply to the reciprocation means (e.g.,cylinder 182, etc.) only when manually actuated trigger 138 is manuallyactuated (or a foot pedal is depressed). When the trigger 138 is pulled,an electrical signal is sent to the flow control switch 219 which, inturn, permits a selected amount of pressurized air to flow into thereciprocation device (e.g., cylinder 182). The trigger switch 138 canhave a number of positions, at which different electrical signals areproduced for enabling flow control switch 219 to allow pressured air toflow to the reciprocation means 182 at different flow rates. This can beused to control the rate of reciprocation of the inner cannula relativeto the outer cannula, providing the surgeon with additional control overthe tissue aspiration process.

[0154] Notably, an improved degree of surgical control and user safetyare provided by the liposuction instrument of the present inventiondescribed above.

[0155] In particular, control circuit 217 prevents the liposuctioninstrument hereof from carrying out cauterization along the length ofits cannula assembly, unless the cannula is reciprocating and/oraspirating. This condition is detected when the trigger 138 is pulled toa particular degree of angular deflection. The reason for providing suchcontrol over the electro-cauterization functionality of the liposuctiondevice hereof is to prevent inadvertent burning of tissue duringliposuction and like procedures.

[0156] The function of the control logic circuit 215 is to enable thecommutation of 20-25 kilohertz electrical signals between the generator216 and the power supply rails 213A and 213B (to energize thepiezo-electric transducers 210 in the base portion of the inner cannula)only when aspirated tissue is flowing through the inner cannula. Thiscondition is detected when the trigger 138 is pulled to a particulardegree of angular deflection.

[0157] The electro-cauterization electrodes of the liposuction deviceshereof can be controlled in a variety of different ways. One way wouldbe to continuously enable RF-based electro-cauterization during sensedtissue aspiration. In such “continuously-enabled” embodiments of thepresent invention, there will typically be no need for external switchesto activate the electro-cauterizing electrodes embodied within thecannula assembly of the present invention.

[0158] Another way would be to enable RF-based electro-cauterization byway of switching RP supply and return signals to the electrodes duringsensed tissue aspiration and supply of an activation signal by thesurgeon. Generation of the activation signal can be realized by manuallyactuating a second trigger, or pushing a button, or depressing a footpedal, external to the hand-supportable housing, or by automaticallydetecting a particular condition along the aspiration channel of thedevice or elsewhere therein.

[0159] While the liposuction instruments described above have been shownto include four symmetrically arranged aspiration apertures, it may bedesired in particular applications to provide a cannula assembly havinginner and outer cannulas with one, two or three aspiration apertures,rather than four as shown in the illustrative embodiments.

[0160] In some applications it may be desired to provide a cannulaassembly having a pair of diametrically opposed aspiration apertures,and an outer cannula with a single aspiration aperture. The outercannula assembly can be adapted to be rotatable in one of two angularpositions about the inner cannula. In the first position, the singleaspiration aperture formed in the outer cannula is aligned inregistration with the first aspiration aperture along the inner cannula.When rotated into its second angular position, the single aspirationaperture of the outer cannula is aligned in registration with the secondaspiration aperture along the inner cannula. The surgeon can easilyswitch the outer cannula between its first and second angular positionsby rotating a small radially extending projection, adjacent thehand-holdable housing, in either a clockwise or counter-clockwisedirection to align the aspiration aperture on the outer cannula inregistration with the selected aspiration aperture on the inner cannula.This feature of the present invention provides the surgeon with theoption of changing which side of the distal end of the cannula assemblyis enabled to aspirate tissue during a liposuction procedure without thenecessity of removing, repositioning and reinserting the cannulaassembly within the housing. This technical feature can be used inconjunction with both electro-cauterizing as well as ultrasoniccauterizing functionalities of the present invention described above.When this aspiration aperture orientation control feature is provided ina liposuction instruments of the present invention having cauterizingelectrodes embedded about the aspiration aperture(s) of a plastic outercannula, an electrical communication mechanism can be embodied withinthe outer cannula the proximal portion thereof and its base portion sothat electrical connectivity can be achieved between the cauterizingelectrode on the outer cannula and its electrically conductive contactpad embedded within the base portion of the outer cannula.

[0161] While the particular embodiments shown and described above haveproven to be useful in many applications in the liposuction art, furthermodifications of the present invention herein disclosed will occur topersons skilled in the art to which the present invention pertains. Allsuch modifications are deemed to be within the scope and spirit of thepresent invention defined by the appended claims.

What is claimed is:
 1. An electro-cauterizing cannula assembly for usewith a powered liposuction device having a hand-holdable housingprovided with a reciprocation means reciprocatable within saidhand-holdable housing and power supply terminals for supplyingradio-frequency (RF) power signal to said cannula assembly duringliposuction operations, said electro-cauterizing cannula assembly beingoperably connectable to said hand-holdable housing and comprising: ahollow inner cannula having a distal end and a proximal end and an innersuction aperture about said inner cannula distal end, said inner cannulaproximal end further including an outlet port and a continuouspassageway which communicates said inner suction aperture with saidoutlet port; a hollow outer cannula having a distal end and a proximalend and on outer suction aperture about said outer cannula distal end,said hollow inner cannula being disposed within at least a portion ofsaid hollow outer and inner cannulas while permitting aspiration throughsaid outer and inner suction apertures, along said continuous passagewayand out of said outlet port; said hollow inner cannula being operablyassociatable with said reciprocation means, and said hollow outercannula being essentially stationary with respect to said hand-holdablehousing, so as to effectuate relative sliding movement between saidhollow inner and outer cannulas when said reciprocation meansreciprocates, so that the location of said aspiration through said outerand inner suction apertures is periodically displaced; andelectro-cauterizing means associated with said hollow inner and outercannulas, for conducting radio-frequency power signals along said hollowinner and outer cannulas and effecting coagulation of protein moleculeswithin the tissue being aspirated through said outer and inner suctionapertures.
 2. The electro-cauterizing cannula assembly of claim 1,wherein said hollow outer cannula further comprises an outer cannulabase extending from said outer cannula proximal end and being adaptedfor releasably connecting with said hand-holdable housing, wherein saidhollow inner cannula is operably associatable with said reciprocationmeans by way of an actuation means disposed in said hand-holdablehousing and reciprocatable by said reciprocation means, and wherein saidhollow inner cannula base further including said outlet port and saidcontinuous passageway, and wherein said hollow outer cannula furthercomprises an outer cannula base which extends from said inner cannulaproximal end and is adapted for releasably connecting with saidhand-holdable housing.
 9. The electro-cauterizing cannula assembly ofclaim 2, wherein said hollow outer cannula is electricallynon-conductive and includes a cauterizing electrode provided about saidhollow outer suction aperture; and wherein said hollow inner cannula iselectrically conductive and the outer cannula base of said hollow innercannula includes electrical means for conducting said RF power signalfrom a first one of said RF power supply terminals in said poweredliposuction device to said hollow inner cannula.
 10. Theelectro-cauterizing cannula assembly of claim 9, wherein said electricalmeans comprises a device inserted within the outer cannula base of saidhollow outer cannula and having an electrical contact element forconducting said RF power signal from said RF power supply terminals tosaid inner cannula while said hollow inner cannula is being reciprocatedwithin said hollow outer cannula.
 11. The electro-cauterizing cannulaassembly of claim 9, wherein the outer cannula base of said hollow outercannula includes an electrical contact element for establishingelectrical contact with one said RF power supply terminals with saidpowered liposuction device.
 12. The electro-cauterizing cannula assemblyof claim 2, wherein said hollow inner cannula is electricallynon-conductive and includes a cauterizing electrode provided about saidinner suction aperture and the inner cannula base of said hollow innercannula includes an electrical connection element for electricallyconnecting said cauterizing electrode with a first one of said RF powersupply terminals within said powered liposuction device; and said outercannula is electrically conductive and the outer cannula base portion ofsaid hollow outer cannula includes electrical means for maintaining saidhollow outer cannula in electrical contact with a second one of said RFpower supply terminals conducting RF power signals to said hollow outercannula.
 13. The electro-cauterizing cannula assembly of claim 12,wherein said electrical means comprises an electrically conductiveelement embedded within the outer cannula base of said hollow outercannula.
 14. The electro-cauterizing cannula assembly of claim 2,wherein said hollow inner and outer cannulas are both electricallynon-conductive; wherein said hollow outer cannula includes an outercauterizing electrode provided about said outer suction aperture andfirst conductive means for conducting RF power signal from the outercannula base of said hollow outer cannula to said first cauterizingelectrode; and wherein said hollow inner cannula includes an innercauterizing electrode provided about said inner suction aperture andsecond conductive means for conducting said RF power signal from saidinner cannula base of said hollow inner cannula to said innercauterizing electrode.
 15. The electro-cauterizing cannula assembly ofclaim 14, wherein the outer cannula base of said hollow outer cannulaincludes a first electrical contact element connected to said firstconductive means for contacting a first one of said power supplyterminals in said powered liposuction device; and wherein the innercannula base of said hollow inner cannula includes a second electricalcontact element connected to said second conductive means for contactinga second one of said power supply terminals in said powered liposuctiondevice.
 16. The electro-cauterizing cannula assembly of claim 15,wherein said first electrical contact element is embedded within theouter cannula base of said hollow outer cannula; and said secondelectrical contact element is embedded within the inner cannula base ofsaid hollow inner cannula.
 17. The electro-cauterizing cannula assemblyof claim 2, wherein said outer suction aperture is elongated in thelongitudinal direction of said hollow inner cannula.
 18. Theelectro-cauterizing cannula assembly of claim 2, wherein saidhand-holdable housing further includes a cannula cavity of cylindricalgeometry, and said inner cannula base comprises a first cylindricalstructure capable of being slidably received within at least a firstportion of said cannula cavity, and wherein a notch means is formed insaid first cylindrical structure and is adapted for releasably engagingwith said actuation means.
 19. The electro-cauterizing cannula assemblyof claim 18, wherein said outer cannula base comprises a secondcylindrical structure capable of being received within at least a secondportion of said cannula cavity, and wherein a flange portion extendsfrom said second cylindrical structure an is adapted for releasablyengaging with a matched recess formed in said cannula cavity.
 22. Theelectro-cauterizing cannula assembly of claim 2, which further comprisesa cannula keying means for maintaining said hollow inner and outercannulas in a predetermined axial alignment so that said outer suctionaperture is in registration with at least a portion of said innerelongated suction aperture as said hollow inner and outer cannulas arecaused to undergo said slidable movement.
 23. The electro-cauterizingcannula assembly of claim 2, which comprises first, second and thirdpairs of said outer and inner suction apertures, each said pair ofsuction apertures being at least partial registration when said hollowinner cannula is inserted within said hollow outer cannula.
 26. Theapparatus of claim 25, said hollow outer cannula further comprises anouter cannula base extending from said outer cannula proximal end andbeing adapted for releasably connecting with said hand-holdable housing,wherein said hollow inner cannula is operably associated with saidreciprocation means by way of an actuation means disposed in saidhand-holdable housing and reciprocatable by said reciprocation means,and wherein said hollow inner cannula base further including said outletport and said continuous passageway, and wherein said hollow outercannula further comprises an outer cannula base which extends from saidinner cannula proximal end and is adapted for releasably connecting withsaid hand-holdable housing.
 33. The apparatus of claim 26, wherein saidhollow outer cannula is electrically non-conductive and includes acauterizing electrode provided about said hollow outer suction aperture;and wherein said hollow inner cannula is electrically conductive and theouter cannula base of said hollow inner cannula includes electricalmeans for conducting said RF power signal from said first one of said RFpower supply terminals to said hollow inner cannula.
 34. The apparatusof claim 33, wherein said electrical means comprises a device insertedwithin the outer cannula base of said hollow outer cannula and having anelectrical contact element for conducting said RF power signals fromsaid RF power supply terminals to said inner cannula while said hollowinner cannula is being reciprocated within said hollow outer cannula.35. The apparatus of claim 33, wherein the outer cannula base of saidhollow outer cannula includes an electrical contact element forestablishing electrical contact with one said RF power supply terminals.36. The apparatus of claim 26, wherein said hollow inner cannula iselectrically non-conductive and includes a cauterizing electrodeprovided about said inner suction aperture and the inner cannula base ofsaid hollow inner cannula includes an electrical connection element ofelectrically connecting said cauterizing electrode with a first one ofsaid RF power supply terminals; and said outer cannula is electricallyconductive and the outer cannula base portion of said hollow outercannula includes electrical means for maintaining said hollow outercannula in electrical contact with a second one of said RF power supplyterminals and conducting RF power signals to said hollow outer cannula.37. The apparatus of claim 36, wherein said electrical means comprisesan electrically conductive element embedded within the outer cannulabase of said hollow outer cannula.
 38. The apparatus of claim 36,wherein said hollow inner and outer cannulas are both electricallynon-conductive; wherein said hollow outer cannula includes an outercauterizing electrode provided about said outer suction aperture andfirst conductive means for conducting said RF power signals from theouter cannula base of said hollow outer cannula to said firstcauterizing electrode; and wherein said hollow inner cannula includes aninner cauterizing electrode provided about said inner suction apertureand second conductive means for conducting said RF power signals fromthe inner cannula base of said hollow inner cannula to said firstcauterizing electrode.
 39. The apparatus of claim 38, wherein the outercannula base of said hollow outer cannula includes a first electricalcontact element connected to said first conductive means for contactinga first one of said RF power supply terminals; and wherein the innercannula base of said hollow inner cannula includes a second electricalcontact element connected to said second conductive means for contactinga second one of said RF power supply terminals.
 40. The apparatus ofclaim 39, wherein said first electrical contact element is embeddedwithin the outer cannula base of said hollow outer cannula; and saidsecond electrical contact element is embedded within the inner cannulabase of said hollow inner cannula.
 41. The apparatus of claim 26 whereinsaid outer suction aperture is elongated in the longitudinal directionof said hollow inner cannula, and said inner suction aperture issubstantially shorter than said outer suction aperture along saidlongitudinal direction.
 42. The apparatus of claim 26, wherein saidhand-holdable housing further includes a cannula cavity of cylindricalgeometry, and said inner cannula base comprises a first cylindricalstructure capable of being slidably received within at least a firstportion of said cannula cavity, and wherein a notch means is formed insaid first cylindrical structure and is adapted for releasably engagingwith said actuation means.
 43. The apparatus of claim 42, wherein saidouter cannula base comprises a second cylindrical structure capable ofbeing received within at least a second portion of said cannula cavity,and wherein a flange portion extends from said second cylindricalstructure and is adapted for releasably engaging with a matched recessformed in said cannula cavity.
 46. The apparatus of claim 26, whichfurther comprises a cannula keying means for maintaining said hollowinner and outer cannulas in a predetermined axial alignment so that saidouter suction aperture is in registration with at least a potion of saidinner elongated suction aperture as said hollow inner and outer cannulasare caused to undergo said slidable movement.
 47. The apparatus of claim26, which comprises first, second and third pairs of said outer andinner suction apertures, each said pair of suction apertures being atleast partial registration when said hollow inner cannula is insertedwithin said hollow outer cannula.
 49. The apparatus of claim 25, whereinsaid RF power signal generator comprises a device, external o saidhand-holdable housing, for generating said RF power signals.
 50. Theapparatus of claim 49, which further comprises a flexible cable forconducting said RF power signals form said external device to said RFpower supply terminals in said power hand-holdable housing.
 51. theapparatus of claim 51, wherein said control means comprises a manuallyactuated trigger.
 53. A power-assisted liposuction instrument, whichcomprises: a cannula assembly; and cauterizing means disposed along saidcannula assembly for cauterizing aspirated tissue during liposuctionprocedures.
 54. The power-assisted liposuction instrument of claim 53,wherein said cauterizing means comprises means for supplyingradio-frequency (RF) power signals to said cannula assembly aboutlocations therealong where aspiration of tissue occurs.
 55. Thepower-assisted liposuction instrument of claim 54, wherein said cannulaassembly comprises: hand-holdable housing; an outer cannula stationarilymounted relative to said hand-holdable housing, and an inner cannulareciprocatable relative to said outer cannula; wherein said outercannula has an outer suction aperture and said inner cannula has aninner suction aperture in registration with said outer suction aperturein registration with said outer suction aperture for aspirating tissuetherethrough.
 56. The power-assisted liposuction instrument of claim 55,wherein said outer cannula is made from a non-conductive material and anelectro-cauterizing electrode element is inserted about said outersuction aperture; and wherein said inner cannula is made from anelectrically conductive material.
 57. The power-assisted liposuctioninstrument of claim 55, wherein said inner and outer cannulas areelectrically isolated by way of thin electrically isolating coatingsapplied to the outer surface of the inner cannulas and/or the interiorsurface of the outer cannula.
 58. The power-assisted liposuctioninstrument of claim 55, wherein said cauterizing means comprises: meansfor producing ultrasonic energy of about 50 KHZ and menas for couplingsaid ultrasonic energy to said inner cannula in order to effect proteincoagulation about said inner and outer suction apertures, to therebyachieve hemostasis during liposuction procedures.
 59. The power-assistedliposuction instrument of claim 58, wherein said ultrasonic energy isproduced by piezoelectric crystals embedded within the base portion ofsaid inner cannula and is driven by electrical signals having afrequency of about 50 KHZ.
 60. The power-assisted liposuction instrumentof claim 55, wherein said cauterizing means comprises: means forproducing ultrasonic energy of about 20-25 KHZ and means for couplingsaid ultrasonic energy to said inner cannula in order to effectliquefaction of tissue about said inner and outer suction apertures, tothereby achieve lipolysis during liposuction procedures.
 61. Thepower-assisted liposuction instrument of claim 60, wherein saidultrasonic energy is produced by piezoelectric crystals embedded withinthe base portion of said inner cannula and is driven by electricalsignals having a frequency of about 20-25 KHZ.